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billme · Jan 22, 2009, 06:31 PM

I have an 11/4" brass gate valve on the outlet of our boiler that is leaking on the top. Not out of the stuffing box, but just below out of a seam. What are the chances that there is some sort of sealant that I can put on there to stop the drip?
Thanks in advance for your help!
Bill

hvac1000 · Jan 22, 2009, 07:20 PM

Clean it up good and try some marine type epoxy. It is the stuff that cures underwater. This way it will cure if wet. I would also take the pressure off the boiler before you apply the epoxy and leave the pressure off till the epoxy is set.

I have used Marine Tex for items such as this.

mygirlsdad77 · Jan 22, 2009, 07:30 PM

Please let us know if this works for you. Never used it before, curious if it is a temp or permanent fix.

billme · Jan 23, 2009, 06:31 PM

OK so I went ahead with a different type of plumbing repair epoxy that I found at Home Cheapo. I did not know how to take the pressure off the boiler and figured that at 10psi or so, it wouldn't matter too much, right? WRONG! So now I have a big blob of gray epoxy on a gate valve that still manages to leak.

My question is, how do you take pressure off the boiler? I didn't want to drain the whole boiler because I wasn't sure if it would fill up and purge the air automatically once I opened up the ball valves again.

Oh, and I noticed the arrows on the circulator pumps, I am apparently dealing with the inlet.

Your help and advice is much appreciated.

Thank you,
Bill

mygirlsdad77 · Jan 23, 2009, 06:51 PM

What hvac is recommending is not to drain system, just to take pressure off. To do this, you will have to shut income water supply(pottable water) at pressure reducing valve. Then open a boiler drain(there should be one located at bottom of boiler, only until the pressure gauge reads zero, then shut drain valve. If you are going to try to use an opoxy again, I suggest using the one hvac suggested(he knows his stuff).

Now, my opinion,, replace valve. I know this may require draining system and repurging and bleeding complete system, but it is a permanent fix. May take some work, but what's done right is done. Please let us know what you decide and how it all works out.

hvac1000 · Jan 23, 2009, 07:43 PM

Remember you have to clean the area well. Wire brush for a few minutes works well. Use the epoxy mentioned and just a thin coat will work. You need to epoxy a bit around the crack also not just a little line where the crack is. You also have to take the pressure off the boiler as was mentioned and you have to allow the epoxy to cure. I have always used a heat lamp to make it cure quicker.

As already mentioned replacing the valve is the best cure.

hvac1000 · Jan 24, 2009, 01:46 AM

billme. One other trick I have used in the past is to braze the crack shut with number 15 stick alloy. If you braze for 1/2 inch before and after the crack with the alloy. This will actually make that area stronger than it was to start with. We only used these patch tricks when we had to for various reasons and as mentioned before replacement of the valve is preferred.